The Shulchan Aruch · Yoreh De'ah
יורה דעה רי״בYoreh De'ah 212
Siman 212 of 402 in Yoreh De'ah — 1 se'if
Se’if 1א׳
הַנּוֹדֵר בַּתּוֹרָה, כְּגוֹן שֶׁאָמַר: פֵּרוֹת אֵלּוּ עָלַי כְּזוֹ, לֹא אָמַר כְּלוּם וְאֵין צָרִיךְ הַתָּרָה אִם הוּא תַּלְמִיד חָכָם; אֲבָל אִם הוּא עַם הָאָרֶץ, צָרִיךְ הַתָּרָה כְּדֵי שֶׁלֹּא יִנְהֲגוּ קַלּוּת רֹאשׁ בִּנְדָרִים. וְאִם נָדַר בַּמֶּה שֶּׁכָּתוּב בָּהּ, אָסוּר שֶׁהֲרֵי כָּתוּב בָּהּ אִסוּר. נְטָלָהּ בְּיָדוֹ וְנָדַר בָּהּ, כְּמִי שֶׁנָּדַר בַּמֶּה שֶּׁכָּתוּב בָּהּ דָּמִי; אֲבָל הַנִּשְׁבָּע בַּתּוֹרָה, בְּכָל עִנְיָן צָרִיךְ הַתָּרָה וְעַיֵּן לְקַמָּן סִימָן רל"ז (בֵּית יוֹסֵף לְעִנְיַן מַעֲשֶׂה).
One who vows by the Torah — such as where he said: these fruits are upon me like this — has said nothing, and requires no release if he is a Torah scholar; but if he is an am ha-aretz (one unlearned in the Torah), he requires release, so that they shall not treat vows with levity. And if he vowed by what is written in it, it is forbidden, for a prohibition is written in it. He took it in his hand and vowed by it — he is as one who vowed by what is written in it. But one who swears by the Torah requires release in every case. And see below, siman 237 (Beit Yosef, as to the practice).
Shulchan Aruch, Yoreh De'ah — Torat Emet 357 edition, via Sefaria — public domain
English rendered from the Hebrew for this app — The Gematria's own rendering program. A rendering of the words, not a ruling; practical halacha is learned with a rav